1. Field of the Invention
The present invention relates generally to recoilless weapons and more specifically to a recoilless weapon with reduced depth of penetration of the disturbed gas field.
2. Description of the Prior Art
In the field of weapon design, the major concern has been the development of recoilless rifles. A portion of a typical recoilless rifle is illustrated in FIG. 1 as including combustion chamber 10 having a single nozzle 12 mounted to exit port 14 at the rear of combustion chamber 10. The recoil of a given weapon is a function of the ratio of the area at the throat A to the area at the exit B of the nozzle, and the total cross-sectional area B. The single nozzle of the prior art, illustrated in FIG. 1, has a venturi longitudinal cross-section.
Other prior art nozzles use the cross-sectional area of the bore or combustion chamber as the throat portion of a venturi and a substantially increased diameter section as the flared portion of the venturi. Positioned on the exit area of the flared portion is generally a center nozzle of the same diameter as the weapon's bore and a plurality of smaller diameter nozzles in a ring around the center nozzle. The recoil compensation of these weapons is produced by the flared portion of the venturi not necessarily the nozzle. While the ring of small diameter nozzle provides rotational stabilization, the center nozzle is the main gas outlet.
The main disadvantages of the nozzles for recoilless weapons of the prior art are that they produce a large danger zone behind the weapon and excessive noise generation. Both of these disadvantages are a function of the penetration depth of the disturbed gas field extending from the rear of the weapon which is directly related to the cross-sectional area B of the nozzle. Since prior art development has been directed to decreasing the recoil of a weapon, major effort has been to increase the cross-sectional area B of the device illustrated in FIG. 1. Thus weapon designers have increased the depth of penetration producing a larger danger zone and excessive noise in order to decrease recoil. A need therefore exists for a recoilless weapon with reduced danger zone and noise levels without sacrificing the recoil reduction characteristics of present weapons.